I created a block of text with $n variable and other variables inside that I want to interpolate on the RHS of a regex. I asked Gemini, and she created the same code I had also tried , which does not work: 
my $myVar='old yeller';
my $b = 'cat $1 dog $2 mouse $myVar';
$_ 'hello sir, I am wally, the greeter';

# Use a substitution to replace the matched parts with $b
s/(hello).+(wally).+/$b/;

[download]
I WANT cat hello dog wally mouse old yeller

I GET 'cat $1 dog $2 mouse $myVar'

the RHS didn't replace $1 , $2 or $myVar. How can I force this? Is there a regex flag? an "eval" somehow?

I told Gemini that our mutual approach failed, and then she suggested: 

s/(hello).+(wally).+/sub { $b =~ s/\$\d+/$$1/g; }/;

[download]
I have a paragraph with lots of substitutions of both $1 $2 etc as well as other vars like $myVar. I want everything in the block interpolated without specifics- I might even have things in the block like $h{test} or $a(indexed to element 3). (I cant seem to enter brackets here). Her answer is way too specific.

as always, it is greatly appreciated that you took time from your busy day to assist me!

In reply to How can I force a regex to interpolate a substituted block? by misterperl

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